1. Field of the Invention
The present invention relates to the separation of propylene oxide and methanol by a liquid/liquid extraction process.
2. Prior Art Description
The separation or removal of methanol from propylene oxide by conventional distillation processes is difficult by reason of the low relative volatility of propylene oxide with respect to methane at higher concentrations such as concentrations above 95 wt. % or so.
Technology has been developed for the production of propylene oxide by oxidative procedures which include the use of a methanol solvent during the oxidation reaction. Illustrative of patents relating to this technology are U.S. Pat. Nos. 4,824,976, 4,833,260, 5,252,758 and the like.
Reaction mixtures produced by this technology comprise the product propylene oxide and the methanol solvent and it is important that the propylene oxide and methanol be separated as conveniently and economically as possible.
In accordance with the present invention, a propylene oxide and methanol solution is subjected to a liquid/liquid extraction using water and a hydrocarbon such as n-octane in order to separate the propylene oxide and methanol.